Laboratory tire test machines are known and are used to conduct tire tread wear tests on tires such as rubber treaded pneumatic or non-pneumatic tires. Generally, a tire and wheel assembly is mounted to a spindle where the tire contacts and rolls against a rotating element such as a drum or the like. The rotating element can have a texture to simulate desired road surfaces. In the alternative or in addition, powder (e.g. talc, silica sand) or other forms of particulate matter can be provided at the tire contact patch. The powder or other particulate matter performs two functions during testing. One function is to provide some control of the friction between the artificial test surface on the rotating element and the tire. The second function is to apply dust to the rubber tread wear particles so they do not stick to the tire or rolling element test surface. The tread wear particles can then be removed by a dust collection system. Various powders and particulates are used. Many are proprietary to the test researchers. Tread wear on the tire is also affected by changes to the test surface as testing progresses. It is often desirable to maintain a surface friction within some range for proper testing. Delivering the proper amount of powder and particulates to the tire contact patch to obtain the desired results is necessary.
On some laboratory tire test machines tire tread wear testing is performed on a curved surface or roller. The curved surface introduces geometry differences in the tire contact patch between testing on the laboratory test machine and real world use of the tire where the contact patch is substantially flat. Adjustments are typically needed to compensate for the test conditions.
The idea of an “intelligent tire” has been advanced. “Intelligent tires” is a term to indicate that the tires have instrumentation or sensor(s) applied to or embedded in the tire to provide feedback to a monitoring system in a vehicle. Work on “intelligent tires” is progressing at tire companies and universities in order that data from the tire is provided to the vehicle monitoring system indicative of roadway friction, tire contact patch size and tire forces. This information can be used during vehicle operation in order to improve vehicle handling and/or stability. The sensor(s) is installed on/in the tire structure or the tire rim to measure, typically, a mechanical change in the tire structure. An algorithm embodied in a computer readable medium that is executed on a processor either within the tire and wheel assembly or outside of the tire and wheel assembly interprets the signal(s) received from the sensor(s). For instance, one method employed by tire companies and universities is to install one or more accelerometers on the inside surface of the tire carcass body or innerliner near the center plane of the tire. The acceleration signal(s) typically is evaluated by the processor executing the algorithm to determine contact patch surface length and characteristics that are indicative of friction between the tire and roadway. It should be noted aspects of the invention described herein do not pertain to algorithms used to evaluate tire friction, but a merely mentioned herein as background information.